Winter Storm and Heavy Snow in Montana, December 3 to 5, 2016

Name: Winter Storm and Heavy Snow in Montana, December 3 to 5, 2016
Start: 2016-12-03T18:00
End: 2016-12-05T11:00
Location: Montana

December 3 to 5, 2016 · NWS MSO · 8 events in 8 counties and zones

Where it happened

Every event with a place to put it; 8 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 8

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS MSO wrote it up.

After an unusually warm November, this event was a large change to cold and wintry conditions for travelers and hunters alike. A warm front followed by a cold front brought periods of heavy snow that caused slick driving conditions to western Montana. Cold temperatures developed at the end of the event contributing to solidifying moisture on the roads and slick roads for the morning commute on Dec. 5th.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Missoula, MT wrote its last area forecast discussion before the first event at Dec 3, 2:43 PM MST, 3 hours 17 minutes earlier.

Area forecast discussion, Dec 3, 2:43 PM MST, 3 hours 17 minutes before

Area Forecast Discussion
National Weather Service Missoula MT
243 PM MST Sat Dec 3 2016

.DISCUSSION...

SNOW, WIND AND TRANSITION TO COLD:
There have only been few changes to the forecast with the
upcoming winter storm. Mountains and passes remain in the path of
moist pacific air that has the right temperature profile to
produce moderate to heavy snowfall tonight through Sunday.
Increased wind will also bring increased concern for very low
visibility in blowing snow Sunday and Sunday evening. Valley
locations are also anticipated to accumulate snow during Sunday
and Sunday night, which will likely accumulate to the biggest snow
event of the season so far. Our main concern, though, is with the
passage of the cold front. The wind, enhanced snowfall, and
colder temperatures could all come together to produce very low
visibility and snow-packed/icy roadways. This cold front will
mainly impact north central Idaho and western Montana during the
afternoon and/or evening.

ARCTIC FRONT:
The northern Flathead Valley through Marias Pass may
start to see arctic air move in from the east as early as Sunday
night, so additional snowfall and gusty east winds may be
observed Sunday night. The arctic front is not expected to move
through western Montana and north central Idaho until Monday
night, so high temperatures on Monday do not look quite as cold
though still below average.

Starting Tuesday morning, we will begin to see Arctic air spill
over the Continental Divide and will lead to dangerous wind chills
of -10F to -25F across western Montana. For central Idaho, a
weather disturbance is expected to bring steady light to moderate
snow on Tuesday and should cause snow to accumulate down to valley
floors. Areas surrounding Whitebird Grade and across the
Clearwater mountains should expect slick travel on Tuesday. Some
light snow showers will also be possible across parts of western
Montana and roads should continue to be slick.

A brief break in precipitation is expected on Wednesday, but cold
temperatures will continue to persist. On Thursday, models have
been consistently showing a warm front moving through central
Idaho and western Montana. With the cold Arctic air in place,
this weather system has the potential for significant valley
snowfall. Stay tuned for more updates next week.

&&

.AVIATION...Banded snow showers in north central Idaho and western
Montana will continue to weaken and dissipate this afternoon,
though cloud cover and obscured terrain will remain. Snow will
again return for north central Idaho and northwest Montana this
evening and the rest of western Montana during Sunday. We have
issued a mix of winter weather advisories/watches/warnings with
impacts from snow, wind, and dropping temperatures extending into
Sunday night. The high terrain and passes are expected to receive
over one foot of snow with blowing snow by Sunday evening. Valleys
are forecast to have many inches of snow. A strong cold front
will also pass through the day and evening so increased winds,
quickly dropping temperatures, moderate to heavy snow, and freeze
up of surfaces are also possible with its passage.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Watch from Sunday morning through Monday morning
     Butte/Blackfoot Region...Missoula/Bitterroot Valleys.

     Winter Storm Warning from midnight tonight to 11 AM MST Monday
     Bitterroot/Sapphire Mountains.

     Winter Storm Warning from midnight tonight to 11 AM MST Monday
     Lower Clark Fork Region.

     Winter Storm Watch from midnight MST tonight through Monday
     morning Flathead/Mission Valleys...Kootenai/Cabinet Region.

     Winter Storm Warning from midnight tonight to 11 AM MST Monday
     West Glacier Region.

     Winter Storm Warning from 11 AM Sunday to 11 AM MST Monday
     Potomac/Seeley Lake Region.

ID...Winter Storm Warning from 8 AM Sunday to 11 AM MST Monday
     Eastern Lemhi County...Western Lemhi County.

     Winter Weather Advisory from 11 PM this evening to 10 AM PST
     Monday ABOVE 3000 FEET for the Lower Hells Canyon/Salmon
     River Region...Orofino/Grangeville Region.

     Winter Storm Warning from 11 PM this evening to 10 AM PST Monday
     Northern Clearwater Mountains...Southern Clearwater
     Mountains.

&&

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

4 winter storm, 2 heavy snow, 2 winter weather. Local standard time, as filed.

Winter Storm, Kootenai/Cabinet Region

When: December 3, 6:00 PM MST to December 5, 8:00 AM MST
Where: Kootenai/Cabinet Region forecast zone
Reported by: Social Media
Coordinates: 48.171, -114.863 (the zone’s center; the record gives no point)

Moderate to heavy snow fell in the valleys and mountains during this event: 21 inches at Stahl Peak at 6000 feet east of Eureka, 12 inches north of Kila at 4000 feet, up to 12 inches in the Eureka area and 4 to 10 inches in other valley locations. Temperatures plummeted to the teens and single digits in the mountains with gusty winds to 35 mph which created dangerous conditions for back-country users.

Winter Storm, Potomac / Seeley Lake Region

When: December 3, 10:00 PM MST to December 5, 7:00 AM MST
Where: Potomac / Seeley Lake Region forecast zone
Reported by: COOP Observer
Coordinates: 46.986, -113.597 (the zone’s center; the record gives no point)

Periods of light to heavy snow fell during this event. A few places did mix with rain in the afternoon of Dec. 4th. While over a foot of snow fell in the mountains, Lindbergh Lake saw 11.6 inches and Seeley Lake saw 3.7 inches of total snowfall. Once the cold front passed through later Sunday, temperatures fell into the teens by Monday morning causing slick spots on the roads. The combination of fresh snow and cold temperatures created dangerous conditions in the back-country.

Winter Storm, Bitterroot / Sapphire Mountains

When: December 4, 12:00 AM MST to December 5, 8:00 AM MST
Where: Bitterroot / Sapphire Mountains forecast zone
Reported by: Public
Coordinates: 46.508, -113.828 (the zone’s center; the record gives no point)

Lost Trail Pass received 8 inches of snow while Lolo Pass saw 13 inches of snow during this event. A strong cold front moved through between the afternoon and evening of Dec. 4th which initiated gusty winds and temperatures dropping into the teens at Lolo Pass and single digits at Lost Trail. The combination of fresh snow, dropping temperatures and wind chills approaching 15 degrees below zero caused dangerous conditions in the back-country for hunters.

Winter Storm, Lower Clark Fork Region

When: December 4, 12:00 AM MST to December 5, 7:00 AM MST
Where: Lower Clark Fork Region forecast zone
Reported by: Department of Highways
Coordinates: 47.286, -114.685 (the zone’s center; the record gives no point)

Moderate to heavy snow contributed to severe driving conditions along Interstate 90 by the afternoon of Dec. 4th which continued through the nighttime hours. Lookout Pass received 16 inches with this storm. Gusty winds and falling temperatures into the teens and single digits after the cold front passage contributed to hazardous conditions in the back-country.

Heavy Snow, West Glacier Region

When: December 4, 2:00 AM MST to 10:00 PM MST
Where: West Glacier Region forecast zone
Reported by: Trained Spotter
Coordinates: 47.971, -114.069 (the zone’s center; the record gives no point)

A trained spotter located near the Blankenship Bridge between West Glacier and Columbia Falls reported near whiteout conditions from heavy snow. A business in Essex reported that 18 inches of snow had fallen with the storm.

Heavy Snow, Flathead/Mission Valleys

When: December 4, 12:00 PM MST to December 5, 9:00 AM MST
Where: Flathead/Mission Valleys forecast zone
Reported by: Trained Spotter
Coordinates: 47.872, -114.424 (the zone’s center; the record gives no point)

Several heavy snow bands, with snow rates up to 5 inch per hour, developed during the day of Dec. 4th then a weak Arctic cold front tracked south during the evening causing widespread snow. As this front lost its steam towards Flathead Lake a heavy snow band formed and impacted much of Highway 35 towards the northeastern Mission Valley. Above freezing temperatures during the day contributed to a snow-over-ice situation by the evening, and very slick conditions lasted into the next morning. Total snowfall amounts include: 9 Columbia Falls, 5.5 Bigfork, 4.6 Glacier Park International Airport.

Winter Weather, Butte / Blackfoot Region

When: December 4, 5:00 PM MST to December 5, 11:00 AM MST
Where: Butte / Blackfoot Region forecast zone
Reported by: Social Media
Coordinates: 46.306, -113.025 (the zone’s center; the record gives no point)

A person from the public tweeted that Interstate 90 eastbound of mile marker 145 was snow and ice covered at 9 am on Dec. 5th. Light snow fell during the evening of Dec. 4th with the cold front passage and temperatures fell into the teens and 20's making road mitigation difficult.

Winter Weather, Missoula / Bitterroot Valleys

When: December 4, 6:00 PM MST to December 5, 2:00 AM MST
Where: Missoula / Bitterroot Valleys forecast zone
Reported by: Law Enforcement
Coordinates: 46.560, -114.023 (the zone’s center; the record gives no point)

Road conditions became slick as snow melted and then refroze during the evening of Dec. 4th continuing into the following morning. The South Hills, including the Miller Creek area of Missoula, saw several slide-offs and accidents due to the slippery roads. This resulted in the local police stating that emergency travel only was advised around 10 pm on the 4th.

What these are

Winter Storm: A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.
Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.
Winter Weather: Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Montana in 2016 Every state in 2016 This day in weather history Warnings in Montana, December 2016

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 667045, 667050, 667044, 667046, 667047, 667351, 667053, 667049.